Dissemination of health behavior change curricula may remain an elusive goal if researchers insist that teachers do most of the work of health behavior change program delivery. We believe that a computer based CVD prevention program, aimed directly at adolescents, can produce significant changes in students' knowledge of CVD processes and risk factor behaviors and, importantly, will prove to be more easily and effectively disseminable than the traditional method of curriculum delivery requiring extensive teacher training and teacher-delivered instruction. Therefore, we propose an efficacy trial to test a customized, interactive, software package focusing on the major CVD risk factors. This software package, which we will develop drawing upon our previous experience in writing CVD prevention instructional software, will combine text, graphics, and digitized sound and be based on programmed instructional principles. We will compare this customized software package with an attention placebo control software condition to provide a control for possible resentful demoralization or compensatory rivalry of teachers as well as the effects of new technology and computer-based presentation of information. Specifically, we propose to randomly assign 6 schools (~2400 9th grade students) to the following conditions: (a) 9th graders in 3 schools will receive CVD prevention education via specialized computer software based on programmed instructional principles; (b) 9 the graders in 3 other schools will receive "attention placebo" software that simply presents general heart health information in a linear sequence. We hypothesize that students who receive the computer-based programmed instructional software package will: (a) Demonstrate significantly greater knowledge gains about CVD risk factor processes that students who receive a "placebo software" control condition; (b) Demonstrate significantly greater self-reported increase in aerobic physical activity; greater self-reported decrease in consumption of fat intake and a higher cessation rate among experimental smokers than students who receive a "placebo software" control condition; (c) Demonstrate significantly greater decreases in resting heart rate that students who receive a "placebo software" control condition (d) Demonstrate significantly reduced increase in BMI than students who receive a "placebo software" control condition. Measures will include: self-reported physical activity, fat intake, cigarette smoking; height, weight, heart rate.